<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>过渡</title>
    <style>

        .container {
            height: 200px;
            position: relative;
        }
        .front,.back{
            width: 200px;
            height: 200px;
            position: absolute;
            left: 0;
            transition: all 3s;

        }
        .front {
            z-index: 1;
            backface-visibility: hidden;
        }
        .back {
            z-index: 0;
        }

        .back {
            border-radius: 100px;
            background-color: #5a6268;
        }
        .container:hover .front{
            transform: rotateY(180deg);
         }
        .container:hover .back {
            transform: rotateY(180deg);
        }


    </style>
</head>
<body>
<div class="container">

    <img class="front" src="images/1.png"/>
    <img class="back"/>
</div>


<div class="box">

</div>
</body>
</html>
